Health surveys repeatedly show that females have higher rates of illness, disability days, and health services use than males. Numerous hypotheses have been proposed to explain the sex differences. They involve health attitudes and beliefs, social roles, social stress. health reporting behavior, life style behaviors, and genetic factors. The purpose of this research is to determine how social and social psychological factors affects reports of symptoms, disability, and other curative health actions, and how these factors explain sex differentials. The basic research design is: A sample of white adults in the Detroit metropolitan area keep health diaries for six weeks. Each day, respondents record information about all symptoms experienced, the preceived severity of those symptoms, restricted activity due to symptoms, medical or dental attention (for symptoms or for preventive reasons), medicine use (for symptoms or preventive reasons), communications with peers and kin about symptoms, mood, and events of the day which were unusual. Two interviews occur--one before the diary period to measure the main predictors, and one at the end of the diary period for retrospective health information and for reactions to the diary task. The Daily Health Records provide the main dependent variables for analysis; the Initial Interview provides the main predictors. Some important innovations of the research are: the use of a health diary among males and persons of low socioeconomic status; self-response (no proxy reports allowed); reports of all symptoms experienced, not just those which prompt some curative action; daily entries in the diaries rather than entries only on symptomatic days; and extensive information on lay communications and medicine use.